ICT equipment such as a server may have a cooling fan within a case thereof so as to prevent the internal temperature of the case from excessively rising due to heat generation by an electronic component such as a CPU. Rotation of the cooling fan allows air to be taken in through an inlet opening formed on the case, and the inside of the case is thereby cooled down. A filter is attached to the inlet opening, so that dust does not enter the case. Even if the cooling fan is attached, however, when the filter is clogged or the cooling fan is down, the quantity of intake air decreases, and the inside of the case cannot be cooled down. In a case where the inside of the case cannot be cooled down, the ICT equipment cannot operate normally.
As a technique for solving such a problem, the following technique is known (e.g., see Patent Document 1). In the technique described in Patent Document 1, firstly, the temperature of intake air and the temperature of a CPU are detected, and an allowable temperature defined for the intake-air temperature is obtained. Then, the CPU temperature is compared with the allowable temperature and, when the CPU temperature is beyond the allowable temperature, it is examined whether the number of rotations of the cooling fan is a set number of rotations. It is notified to the user that the filter is clogged when the number of rotations of the cooling fan is the set number of rotations, whereas it is notified to the user that the cooling fan is down when the number of rotations of the cooling fan is not the set number of rotations.    [Patent Document 1] Japanese Unexamined Patent Application Publication No. JP-A 2006-127283
In a case where the operational status of the ICT equipment is constant, it is possible to accurately detect an abnormality such as clogging of the filter by the technique described in Patent Document 1. However, in the technique described in Patent Document 1, the CPU temperature is compared with the allowable temperature defined for the intake-air temperature, and it is thereby determined whether an abnormality such as clogging of the filter is occurring. Therefore, in a case where the operational status of the ICT equipment is not constant, it may be impossible to detect an abnormality such as clogging or, by contrast, it may be determined that an abnormality such as clogging is occurring in spite of no abnormality. For example, in the latest ICT equipment, the amount of heat generated by the CPU substantially triples depending on the operational status and this fact is not considered in the technique described in Patent Document 1, so that it is impossible to accurately detect an abnormality such as clogging of the filter.